<script type=text/javascript src=Class.js></script>
<script type=text/javascript>
/* Simple JavaScript Inheritance
 * By John Resig http://ejohn.org/
 * MIT Licensed.
 */
// Inspired by base2 and Prototype
(function(){
  var initializing = false, fnTest = /xyz/.test(function(){xyz;}) ? /\b_super\b/ : /.*/;
  // The base Class implementation (does nothing)
  this.$$Class = function(){};
  
  // Create a new Class that inherits from this class
  $$Class.extend = function(prop) {
    var _super = this.prototype;
    
    // Instantiate a base class (but only create the instance,
    // don't run the init constructor)
    initializing = true;
    var prototype = new this();
    initializing = false;
    
    // Copy the properties over onto the new prototype
    for (var name in prop) {
      // Check if we're overwriting an existing function
      prototype[name] = typeof prop[name] == "function" && 
        typeof _super[name] == "function" && fnTest.test(prop[name]) ?
        (function(name, fn){
          return function() {
            var tmp = this._super;
            
            // Add a new ._super() method that is the same method
            // but on the super-class
            this._super = _super[name];
            
            // The method only need to be bound temporarily, so we
            // remove it when we're done executing
            var ret = fn.apply(this, arguments);        
            this._super = tmp;
            
            return ret;
          };
        })(name, prop[name]) :
        prop[name];
    }
    
    // The dummy class constructor
    function Class() {
      // All construction is actually done in the init method
      if ( !initializing && this.init )
        this.init.apply(this, arguments);
    }
    
    // Populate our constructed prototype object
    Class.prototype = prototype;
    
    // Enforce the constructor to be what we expect
    Class.constructor = Class;

    // And make this class extendable
    Class.extend = arguments.callee;
    
    return Class;
  };
})();

</script>
<script type=text/javascript>
Class('Person', {
init : function (sex, age) {
this.sex = sex;
this.age = age;
},
speak : function (msg) {
console.log(msg);
},
getAge: function () {
    return this.age;
}
});



Class('Singer', Person, {
init : function (sex, age, song) {
this.song = song;
},
sing: function () {
console.log(this.song + '...')
this.$super.speak('asd')
},
getAge: function () {
    return this.$super.getAge();
}
});
var p2 = new Singer('male', 20, 'beat it');
console.log(p2.song)




























var Person = $$Class.extend({
init : function (sex, age) {
this.sex = sex;
this.age = age;
},
speak : function (msg) {
console.log(msg);
},
getAge: function () {
    return this.age;
}
});



var Singer = Person.extend({
init : function (sex, age, song) {
this.song = song;
},
sing: function () {
console.log(this.song + '...')
this.$super.speak('asd')
}
});
var p2p = new Singer('male', 20, 'beat it');
console.log(p2p.song)
/*
Class('A.Avril', Singer, {
init : function (sex, age, song) {
this.albums = ['let go', 'under my skin', 'the best damn thing', 'what the hell'];
},
selectAlbums: function () {
return this.albums[Math.floor(Math.random() * 4)];
},
sing: function () {
this.$super.speak(this.selectAlbums());
}
})

var p3 = new A.Avril('female', 20, '');
console.log(p3.sex)
*/
</script>
